【摘要】 利用高温固相法合成了 Ｙ１．９５－ｘＧｄｘＳｉＯ５：Ｅｕ０．０５（ｘ＝０．６ｍｏｌ％）荧光体。结构测定表明所合成的荧光体为单斜晶系的Ｘ２型Ｙ２ＳｉＯ５相，空间群为Ｂ２／ｂ。真空紫外光谱表明：随着Ｇｄ３＋含量的增加，在１９２ｕｍ附近，出现了Ｇｄ＋的激发峰，且此峰的强度随着Ｇｄ３＋含量的增加而增大；同时位于１５０～１８５ｎｍ之间的基质吸收带的强度也增大；而位于２００～３００ｎｍ之间的Ｅｕ的电行迁移带的强度却随着Ｇｄ３＋含量的增加而降低。更多还原

【Abstract】 Color plasma display panel(PDP) is the most promising flat display for the large area display. Phosphors used in PDP are excited with vacuum-ultraviolet radiation. Naturally, the phosphors are required to have a good quantum efficiency in the region below 200um. Some silicates have stronger absorption in the VUV region. Therefore, it is important to investigate silicates. On the other hand, oxyorthosilicates have good thermal stability and chemistry stability, and also are good host for luminescent materials under UV excitation. However, optical properties of Y2 - xGdxSiO5: Eu in the VUV range have not been reported up to now. Y1.95-xGdxSiO5: EUO.05 were prepared at 1 200℃ for two hours with NH4F flux by solid-state reaction. Y1.95-xGdxSiO5: EUO.05 are polymorphic and crytallizable in the monoclinic X2 type with space group B2/b. The excitation spectra of Y1.95 SiO5: EuO.05 monitored at 612um consists of a broad band at 220 - 300um corresponding to the charge transfer band of Eu, and a number of lines which could be assigned to the f - f transition of Eu3+ for 300 - 540nm, and the strongest excited peak lies at 396nm. The emission spectrum of Y1.95 - xSiO5: EuO.05 phosphors excited under 396mn irradiation consists of four groups of emission lines in the rang of 560-720nm. The maximum emission peak is located at 612urn. One luminescence line at 580nm, three lines at 590 - 596nm, five lines at 610 - 630nm and three lines at 685 - 705nm are assigned to the transitions 5D0→7F0, 5DO→7F1, 5DO→7F2, 5D0→7F4, respectively. When a x (x = 0. 2, 0. 4, 0. 6) mol faction of gadolinium is incorporated into the host lattice, the location of absorption peaks of Eu3+ shown in VU-vis excitation specturm of Y1.95 - xGdxSiO5: Eu0.05 are not changed, but the relative intensities of these peaks decrease with increasing Gd3+ concentration. In the vacuum-ultraviolet region, the new absorption peak near 192nm appears. The intensity of the new peak assigned to the absorption of 6Gj configuration of Gd3+ increases with increasing Gd3+ concentration until 0.4 mol%, and then, the intensity decreases. The intensity of the host absorption band of the phosphors at 150 - 185nm is enhanced while the intensity of the charge transfer band of Eu decreases with increasing Gd3+ concentration. Generally speaking, when a x mol fraction of gadolinium is incorporated into the host lattice, the luminescent intensity in vacuum-ultraviolet region increases in spite of the decreasing in VU-vis region. That is in favor of enhanching the luminescent intensity of phosphors used in PDP.更多还原